The case of Cushing's disease imaging by SPECT examination without manifestation of adenoma in MRI examination

BACKGROUND: The aim of our study was to evaluate the possibility of imaging the pathological accumulation of 99mTc-MIBI in the pituitary gland in patients with Cushing's disease when MRI examination does not show microadenomas. MATERIAL AND METHODS: Cushing's disease was diagnosed in a 27 year old male on the basis of clinical and biochemical findings. The blood cortisol level of the patient was elevated (the average level was 47 ug/dl) and it showed no changeability of day and night rhythm. RESULTS: In the patient with Cushing's disease, during the SPECT examination, an increased accumulation of 99mTc-MIBI in the pituitary gland was noticed. MRI scanning was negative. CONCLUSION: Single photon emission computed tomography using 99mTc-MIBI is a useful and sensitive means of pituitary gland microadenoma detection in patients with Cushing's disease when microadenoma is not detected during MRI scanning and when the results of dexamethasone suppression test is positive.